The present invention relates to overhead cranes and particularly to upper blocks of overhead cranes. More particularly, the present invention relates to failure proof mechanisms for upper blocks of overhead cranes.
Conventional overhead cranes include an upper block that, in combination with a lower block and a drum, is used to raise or lower a hook or other lifting mechanism attached to the lower block. Often, conventional overhead cranes include failure proof mechanisms within the upper block to shut down the crane if an overload or uneven-load condition is present.